/***************************************************************************/
/*                                                                         */
/*  ttsbit.c                                                               */
/*                                                                         */
/*    TrueType and OpenType embedded bitmap support (body).                */
/*                                                                         */
/*  Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,   */
/*            2010 by                                                      */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/

#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_STREAM_H
#include FT_TRUETYPE_TAGS_H

/*
 *  Alas, the memory-optimized sbit loader can't be used when implementing
 *  the `old internals' hack
 */
#ifndef FT_CONFIG_OPTION_OLD_INTERNALS

#include "ttsbit0.c"

#else /* FT_CONFIG_OPTION_OLD_INTERNALS */

#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_STREAM_H
#include FT_TRUETYPE_TAGS_H
#include "ttsbit.h"

#include "sferrors.h"


/*************************************************************************/
/*                                                                       */
/* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
/* messages during execution.                                            */
/*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_ttsbit


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    blit_sbit                                                          */
/*                                                                       */
/* <Description>                                                         */
/*    Blits a bitmap from an input stream into a given target.  Supports */
/*    x and y offsets as well as byte padded lines.                      */
/*                                                                       */
/* <Input>                                                               */
/*    target      :: The target bitmap/pixmap.                           */
/*                                                                       */
/*    source      :: The input packed bitmap data.                       */
/*                                                                       */
/*    line_bits   :: The number of bits per line.                        */
/*                                                                       */
/*    byte_padded :: A flag which is true if lines are byte-padded.      */
/*                                                                       */
/*    x_offset    :: The horizontal offset.                              */
/*                                                                       */
/*    y_offset    :: The vertical offset.                                */
/*                                                                       */
/* <Note>                                                                */
/*    IMPORTANT: The x and y offsets are relative to the top corner of   */
/*               the target bitmap (unlike the normal TrueType           */
/*               convention).  A positive y offset indicates a downwards */
/*               direction!                                              */
/*                                                                       */
static void
blit_sbit( FT_Bitmap*  target,
           FT_Byte*    source,
           FT_Int      line_bits,
           FT_Bool     byte_padded,
           FT_Int      x_offset,
           FT_Int      y_offset,
           FT_Int      source_height )
{
  FT_Byte*   line_buff;
  FT_Int     line_incr;
  FT_Int     height;

  FT_UShort  acc;
  FT_UInt    loaded;


  /* first of all, compute starting write position */
  line_incr = target->pitch;
  line_buff = target->buffer;

  if ( line_incr < 0 )
    line_buff -= line_incr * ( target->rows - 1 );

  line_buff += ( x_offset >> 3 ) + y_offset * line_incr;

  /***********************************************************************/
  /*                                                                     */
  /* We use the extra-classic `accumulator' trick to extract the bits    */
  /* from the source byte stream.                                        */
  /*                                                                     */
  /* Namely, the variable `acc' is a 16-bit accumulator containing the   */
  /* last `loaded' bits from the input stream.  The bits are shifted to  */
  /* the upmost position in `acc'.                                       */
  /*                                                                     */
  /***********************************************************************/

  acc    = 0;  /* clear accumulator   */
  loaded = 0;  /* no bits were loaded */

  for ( height = source_height; height > 0; height-- )
  {
    FT_Byte*  cur   = line_buff;        /* current write cursor          */
    FT_Int    count = line_bits;        /* # of bits to extract per line */
    FT_Byte   shift = (FT_Byte)( x_offset & 7 ); /* current write shift  */
    FT_Byte   space = (FT_Byte)( 8 - shift );


    /* first of all, read individual source bytes */
    if ( count >= 8 )
    {
      count -= 8;
      {
        do
        {
          FT_Byte  val;


          /* ensure that there are at least 8 bits in the accumulator */
          if ( loaded < 8 )
          {
            acc    |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded ));
            loaded += 8;
          }

          /* now write one byte */
          val = (FT_Byte)( acc >> 8 );
          if ( shift )
          {
            cur[0] |= (FT_Byte)( val >> shift );
            cur[1] |= (FT_Byte)( val << space );
          }
          else
            cur[0] |= val;

          cur++;
          acc   <<= 8;  /* remove bits from accumulator */
          loaded -= 8;
          count  -= 8;

        } while ( count >= 0 );
      }

      /* restore `count' to correct value */
      count += 8;
    }

    /* now write remaining bits (count < 8) */
    if ( count > 0 )
    {
      FT_Byte  val;


      /* ensure that there are at least `count' bits in the accumulator */
      if ( (FT_Int)loaded < count )
      {
        acc    |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded ));
        loaded += 8;
      }

      /* now write remaining bits */
      val     = (FT_Byte)( ( (FT_Byte)( acc >> 8 ) ) & ~( 0xFF >> count ) );
      cur[0] |= (FT_Byte)( val >> shift );

      if ( count > space )
        cur[1] |= (FT_Byte)( val << space );

      acc   <<= count;
      loaded -= count;
    }

    /* now, skip to next line */
    if ( byte_padded )
    {
      acc    = 0;
      loaded = 0;   /* clear accumulator on byte-padded lines */
    }

    line_buff += line_incr;
  }
}


static const FT_Frame_Field  sbit_metrics_fields[] =
{
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_SBit_MetricsRec

  FT_FRAME_START( 8 ),
    FT_FRAME_BYTE( height ),
    FT_FRAME_BYTE( width ),

    FT_FRAME_CHAR( horiBearingX ),
    FT_FRAME_CHAR( horiBearingY ),
    FT_FRAME_BYTE( horiAdvance ),

    FT_FRAME_CHAR( vertBearingX ),
    FT_FRAME_CHAR( vertBearingY ),
    FT_FRAME_BYTE( vertAdvance ),
  FT_FRAME_END
};


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    Load_SBit_Const_Metrics                                            */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the metrics for `EBLC' index tables format 2 and 5.          */
/*                                                                       */
/* <Input>                                                               */
/*    range  :: The target range.                                        */
/*                                                                       */
/*    stream :: The input stream.                                        */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
static FT_Error
Load_SBit_Const_Metrics( TT_SBit_Range  range,
                         FT_Stream      stream )
{
  FT_Error  error;


  if ( FT_READ_ULONG( range->image_size ) )
    return error;

  return FT_STREAM_READ_FIELDS( sbit_metrics_fields, &range->metrics );
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    Load_SBit_Range_Codes                                              */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the range codes for `EBLC' index tables format 4 and 5.      */
/*                                                                       */
/* <Input>                                                               */
/*    range        :: The target range.                                  */
/*                                                                       */
/*    stream       :: The input stream.                                  */
/*                                                                       */
/*    load_offsets :: A flag whether to load the glyph offset table.     */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
static FT_Error
Load_SBit_Range_Codes( TT_SBit_Range  range,
                       FT_Stream      stream,
                       FT_Bool        load_offsets )
{
  FT_Error   error;
  FT_ULong   count, n, size;
  FT_Memory  memory = stream->memory;


  if ( FT_READ_ULONG( count ) )
    goto Exit;

  range->num_glyphs = count;

  /* Allocate glyph offsets table if needed */
  if ( load_offsets )
  {
    if ( FT_NEW_ARRAY( range->glyph_offsets, count ) )
      goto Exit;

    size = count * 4L;
  }
  else
    size = count * 2L;

  /* Allocate glyph codes table and access frame */
  if ( FT_NEW_ARRAY ( range->glyph_codes, count ) ||
       FT_FRAME_ENTER( size )                     )
    goto Exit;

  for ( n = 0; n < count; n++ )
  {
    range->glyph_codes[n] = FT_GET_USHORT();

    if ( load_offsets )
      range->glyph_offsets[n] = (FT_ULong)range->image_offset +
                                FT_GET_USHORT();
  }

  FT_FRAME_EXIT();

Exit:
  return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    Load_SBit_Range                                                    */
/*                                                                       */
/* <Description>                                                         */
/*    Loads a given `EBLC' index/range table.                            */
/*                                                                       */
/* <Input>                                                               */
/*    range  :: The target range.                                        */
/*                                                                       */
/*    stream :: The input stream.                                        */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
static FT_Error
Load_SBit_Range( TT_SBit_Range  range,
                 FT_Stream      stream )
{
  FT_Error   error;
  FT_Memory  memory = stream->memory;


  switch( range->index_format )
  {
  case 1:   /* variable metrics with 4-byte offsets */
  case 3:   /* variable metrics with 2-byte offsets */
    {
      FT_ULong  num_glyphs, n;
      FT_Int    size_elem;
      FT_Bool   large = FT_BOOL( range->index_format == 1 );



      if ( range->last_glyph < range->first_glyph )
      {
        error = SFNT_Err_Invalid_File_Format;
        goto Exit;
      }

      num_glyphs        = range->last_glyph - range->first_glyph + 1L;
      range->num_glyphs = num_glyphs;
      num_glyphs++;                       /* XXX: BEWARE - see spec */

      size_elem = large ? 4 : 2;

      if ( FT_NEW_ARRAY( range->glyph_offsets, num_glyphs ) ||
           FT_FRAME_ENTER( num_glyphs * size_elem )         )
        goto Exit;

      for ( n = 0; n < num_glyphs; n++ )
        range->glyph_offsets[n] = (FT_ULong)( range->image_offset +
                                              ( large ? FT_GET_ULONG()
                                                      : FT_GET_USHORT() ) );
      FT_FRAME_EXIT();
    }
    break;

  case 2:   /* all glyphs have identical metrics */
    error = Load_SBit_Const_Metrics( range, stream );
    break;

  case 4:
    error = Load_SBit_Range_Codes( range, stream, 1 );
    break;

  case 5:
    error = Load_SBit_Const_Metrics( range, stream );
    if ( !error )
      error = Load_SBit_Range_Codes( range, stream, 0 );
    break;

  default:
    error = SFNT_Err_Invalid_File_Format;
  }

Exit:
  return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_eblc                                                  */
/*                                                                       */
/* <Description>                                                         */
/*    Loads the table of embedded bitmap sizes for this face.            */
/*                                                                       */
/* <Input>                                                               */
/*    face   :: The target face object.                                  */
/*                                                                       */
/*    stream :: The input stream.                                        */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_eblc( TT_Face    face,
                   FT_Stream  stream )
{
  FT_Error   error  = SFNT_Err_Ok;
  FT_Memory  memory = stream->memory;
  FT_Fixed   version;
  FT_ULong   num_strikes;
  FT_ULong   table_base;

  static const FT_Frame_Field  sbit_line_metrics_fields[] =
  {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_SBit_LineMetricsRec

    /* no FT_FRAME_START */
      FT_FRAME_CHAR( ascender ),
      FT_FRAME_CHAR( descender ),
      FT_FRAME_BYTE( max_width ),

      FT_FRAME_CHAR( caret_slope_numerator ),
      FT_FRAME_CHAR( caret_slope_denominator ),
      FT_FRAME_CHAR( caret_offset ),

      FT_FRAME_CHAR( min_origin_SB ),
      FT_FRAME_CHAR( min_advance_SB ),
      FT_FRAME_CHAR( max_before_BL ),
      FT_FRAME_CHAR( min_after_BL ),
      FT_FRAME_CHAR( pads[0] ),
      FT_FRAME_CHAR( pads[1] ),
    FT_FRAME_END
  };

  static const FT_Frame_Field  strike_start_fields[] =
  {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_SBit_StrikeRec

    /* no FT_FRAME_START */
      FT_FRAME_ULONG( ranges_offset ),
      FT_FRAME_SKIP_LONG,
      FT_FRAME_ULONG( num_ranges ),
      FT_FRAME_ULONG( color_ref ),
    FT_FRAME_END
  };

  static const FT_Frame_Field  strike_end_fields[] =
  {
    /* no FT_FRAME_START */
      FT_FRAME_USHORT( start_glyph ),
      FT_FRAME_USHORT( end_glyph ),
      FT_FRAME_BYTE  ( x_ppem ),
      FT_FRAME_BYTE  ( y_ppem ),
      FT_FRAME_BYTE  ( bit_depth ),
      FT_FRAME_CHAR  ( flags ),
    FT_FRAME_END
  };


  face->num_sbit_strikes = 0;

  /* this table is optional */
  error = face->goto_table( face, TTAG_EBLC, stream, 0 );
  if ( error )
    error = face->goto_table( face, TTAG_bloc, stream, 0 );
  if ( error )
    goto Exit;

  table_base = FT_STREAM_POS();
  if ( FT_FRAME_ENTER( 8L ) )
    goto Exit;

  version     = FT_GET_LONG();
  num_strikes = FT_GET_ULONG();

  FT_FRAME_EXIT();

  /* check version number and strike count */
  if ( version     != 0x00020000L ||
       num_strikes >= 0x10000L    )
  {
    FT_ERROR(( "tt_face_load_sbit_strikes: invalid table version\n" ));
    error = SFNT_Err_Invalid_File_Format;

    goto Exit;
  }

  /* allocate the strikes table */
  if ( FT_NEW_ARRAY( face->sbit_strikes, num_strikes ) )
    goto Exit;

  face->num_sbit_strikes = num_strikes;

  /* now read each strike table separately */
  {
    TT_SBit_Strike  strike = face->sbit_strikes;
    FT_ULong        count  = num_strikes;


    if ( FT_FRAME_ENTER( 48L * num_strikes ) )
      goto Exit;

    while ( count > 0 )
    {
      if ( FT_STREAM_READ_FIELDS( strike_start_fields, strike )             ||
           FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->hori ) ||
           FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->vert ) ||
           FT_STREAM_READ_FIELDS( strike_end_fields, strike )               )
        break;

      count--;
      strike++;
    }

    FT_FRAME_EXIT();
  }

  /* allocate the index ranges for each strike table */
  {
    TT_SBit_Strike  strike = face->sbit_strikes;
    FT_ULong        count  = num_strikes;


    while ( count > 0 )
    {
      TT_SBit_Range  range;
      FT_ULong       count2 = strike->num_ranges;


      /* read each range */
      if ( FT_STREAM_SEEK( table_base + strike->ranges_offset ) ||
           FT_FRAME_ENTER( strike->num_ranges * 8L )            )
        goto Exit;

      if ( FT_NEW_ARRAY( strike->sbit_ranges, strike->num_ranges ) )
        goto Exit;

      range = strike->sbit_ranges;
      while ( count2 > 0 )
      {
        range->first_glyph  = FT_GET_USHORT();
        range->last_glyph   = FT_GET_USHORT();
        range->table_offset = table_base + strike->ranges_offset +
                                FT_GET_ULONG();
        count2--;
        range++;
      }

      FT_FRAME_EXIT();

      /* Now, read each index table */
      count2 = strike->num_ranges;
      range  = strike->sbit_ranges;
      while ( count2 > 0 )
      {
        /* Read the header */
        if ( FT_STREAM_SEEK( range->table_offset ) ||
             FT_FRAME_ENTER( 8L )                  )
          goto Exit;

        range->index_format = FT_GET_USHORT();
        range->image_format = FT_GET_USHORT();
        range->image_offset = FT_GET_ULONG();

        FT_FRAME_EXIT();

        error = Load_SBit_Range( range, stream );
        if ( error )
          goto Exit;

        count2--;
        range++;
      }

      count--;
      strike++;
    }
  }

Exit:
  return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_free_eblc                                                  */
/*                                                                       */
/* <Description>                                                         */
/*    Releases the embedded bitmap tables.                               */
/*                                                                       */
/* <Input>                                                               */
/*    face :: The target face object.                                    */
/*                                                                       */
FT_LOCAL_DEF( void )
tt_face_free_eblc( TT_Face  face )
{
  FT_Memory       memory       = face->root.memory;
  TT_SBit_Strike  strike       = face->sbit_strikes;
  TT_SBit_Strike  strike_limit = strike + face->num_sbit_strikes;


  if ( strike )
  {
    for ( ; strike < strike_limit; strike++ )
    {
      TT_SBit_Range  range       = strike->sbit_ranges;
      TT_SBit_Range  range_limit = range + strike->num_ranges;


      if ( range )
      {
        for ( ; range < range_limit; range++ )
        {
          /* release the glyph offsets and codes tables */
          /* where appropriate                          */
          FT_FREE( range->glyph_offsets );
          FT_FREE( range->glyph_codes );
        }
      }
      FT_FREE( strike->sbit_ranges );
      strike->num_ranges = 0;
    }
    FT_FREE( face->sbit_strikes );
  }
  face->num_sbit_strikes = 0;
}


FT_LOCAL_DEF( FT_Error )
tt_face_set_sbit_strike( TT_Face          face,
                         FT_Size_Request  req,
                         FT_ULong*        astrike_index )
{
  return FT_Match_Size( (FT_Face)face, req, 0, astrike_index );
}


FT_LOCAL_DEF( FT_Error )
tt_face_load_strike_metrics( TT_Face           face,
                             FT_ULong          strike_index,
                             FT_Size_Metrics*  metrics )
{
  TT_SBit_Strike  strike;


  if ( strike_index >= face->num_sbit_strikes )
    return SFNT_Err_Invalid_Argument;

  strike = face->sbit_strikes + strike_index;

  metrics->x_ppem = strike->x_ppem;
  metrics->y_ppem = strike->y_ppem;

  metrics->ascender  = strike->hori.ascender << 6;
  metrics->descender = strike->hori.descender << 6;

  /* XXX: Is this correct? */
  metrics->max_advance = ( strike->hori.min_origin_SB  +
                           strike->hori.max_width      +
                           strike->hori.min_advance_SB ) << 6;

  metrics->height = metrics->ascender - metrics->descender;

  return SFNT_Err_Ok;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    find_sbit_range                                                    */
/*                                                                       */
/* <Description>                                                         */
/*    Scans a given strike's ranges and return, for a given glyph        */
/*    index, the corresponding sbit range, and `EBDT' offset.            */
/*                                                                       */
/* <Input>                                                               */
/*    glyph_index   :: The glyph index.                                  */
/*                                                                       */
/*    strike        :: The source/current sbit strike.                   */
/*                                                                       */
/* <Output>                                                              */
/*    arange        :: The sbit range containing the glyph index.        */
/*                                                                       */
/*    aglyph_offset :: The offset of the glyph data in `EBDT' table.     */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means the glyph index was found.           */
/*                                                                       */
static FT_Error
find_sbit_range( FT_UInt          glyph_index,
                 TT_SBit_Strike   strike,
                 TT_SBit_Range   *arange,
                 FT_ULong        *aglyph_offset )
{
  TT_SBit_RangeRec  *range, *range_limit;


  /* check whether the glyph index is within this strike's */
  /* glyph range                                           */
  if ( glyph_index < (FT_UInt)strike->start_glyph ||
       glyph_index > (FT_UInt)strike->end_glyph   )
    goto Fail;

  /* scan all ranges in strike */
  range       = strike->sbit_ranges;
  range_limit = range + strike->num_ranges;
  if ( !range )
    goto Fail;

  for ( ; range < range_limit; range++ )
  {
    if ( glyph_index >= (FT_UInt)range->first_glyph &&
         glyph_index <= (FT_UInt)range->last_glyph  )
    {
      FT_UShort  delta = (FT_UShort)( glyph_index - range->first_glyph );


      switch ( range->index_format )
      {
      case 1:
      case 3:
        *aglyph_offset = range->glyph_offsets[delta];
        break;

      case 2:
        *aglyph_offset = range->image_offset +
                         range->image_size * delta;
        break;

      case 4:
      case 5:
        {
          FT_ULong  n;


          for ( n = 0; n < range->num_glyphs; n++ )
          {
            if ( (FT_UInt)range->glyph_codes[n] == glyph_index )
            {
              if ( range->index_format == 4 )
                *aglyph_offset = range->glyph_offsets[n];
              else
                *aglyph_offset = range->image_offset +
                                 n * range->image_size;
              goto Found;
            }
          }
        }

      /* fall-through */
      default:
        goto Fail;
      }

    Found:
      /* return successfully! */
      *arange  = range;
      return SFNT_Err_Ok;
    }
  }

Fail:
  *arange        = 0;
  *aglyph_offset = 0;

  return SFNT_Err_Invalid_Argument;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_find_sbit_image                                                 */
/*                                                                       */
/* <Description>                                                         */
/*    Checks whether an embedded bitmap (an `sbit') exists for a given   */
/*    glyph, at a given strike.                                          */
/*                                                                       */
/* <Input>                                                               */
/*    face          :: The target face object.                           */
/*                                                                       */
/*    glyph_index   :: The glyph index.                                  */
/*                                                                       */
/*    strike_index  :: The current strike index.                         */
/*                                                                       */
/* <Output>                                                              */
/*    arange        :: The SBit range containing the glyph index.        */
/*                                                                       */
/*    astrike       :: The SBit strike containing the glyph index.       */
/*                                                                       */
/*    aglyph_offset :: The offset of the glyph data in `EBDT' table.     */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.  Returns                    */
/*    SFNT_Err_Invalid_Argument if no sbit exists for the requested      */
/*    glyph.                                                             */
/*                                                                       */
FT_LOCAL( FT_Error )
tt_find_sbit_image( TT_Face          face,
                    FT_UInt          glyph_index,
                    FT_ULong         strike_index,
                    TT_SBit_Range   *arange,
                    TT_SBit_Strike  *astrike,
                    FT_ULong        *aglyph_offset )
{
  FT_Error        error;
  TT_SBit_Strike  strike;


  if ( !face->sbit_strikes                        ||
       ( face->num_sbit_strikes <= strike_index ) )
    goto Fail;

  strike = &face->sbit_strikes[strike_index];

  error = find_sbit_range( glyph_index, strike,
                           arange, aglyph_offset );
  if ( error )
    goto Fail;

  *astrike = strike;

  return SFNT_Err_Ok;

Fail:
  /* no embedded bitmap for this glyph in face */
  *arange        = 0;
  *astrike       = 0;
  *aglyph_offset = 0;

  return SFNT_Err_Invalid_Argument;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_load_sbit_metrics                                               */
/*                                                                       */
/* <Description>                                                         */
/*    Gets the big metrics for a given SBit.                             */
/*                                                                       */
/* <Input>                                                               */
/*    stream      :: The input stream.                                   */
/*                                                                       */
/*    range       :: The SBit range containing the glyph.                */
/*                                                                       */
/* <Output>                                                              */
/*    big_metrics :: A big SBit metrics structure for the glyph.         */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.                             */
/*                                                                       */
/* <Note>                                                                */
/*    The stream cursor must be positioned at the glyph's offset within  */
/*    the `EBDT' table before the call.                                  */
/*                                                                       */
/*    If the image format uses variable metrics, the stream cursor is    */
/*    positioned just after the metrics header in the `EBDT' table on    */
/*    function exit.                                                     */
/*                                                                       */
FT_LOCAL( FT_Error )
tt_load_sbit_metrics( FT_Stream        stream,
                      TT_SBit_Range    range,
                      TT_SBit_Metrics  metrics )
{
  FT_Error  error = SFNT_Err_Ok;


  switch ( range->image_format )
  {
  case 1:
  case 2:
  case 8:
    /* variable small metrics */
    {
      TT_SBit_SmallMetricsRec  smetrics;

      static const FT_Frame_Field  sbit_small_metrics_fields[] =
      {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_SBit_SmallMetricsRec

        FT_FRAME_START( 5 ),
          FT_FRAME_BYTE( height ),
          FT_FRAME_BYTE( width ),
          FT_FRAME_CHAR( bearingX ),
          FT_FRAME_CHAR( bearingY ),
          FT_FRAME_BYTE( advance ),
        FT_FRAME_END
      };


      /* read small metrics */
      if ( FT_STREAM_READ_FIELDS( sbit_small_metrics_fields, &smetrics ) )
        goto Exit;

      /* convert it to a big metrics */
      metrics->height       = smetrics.height;
      metrics->width        = smetrics.width;
      metrics->horiBearingX = smetrics.bearingX;
      metrics->horiBearingY = smetrics.bearingY;
      metrics->horiAdvance  = smetrics.advance;

      /* these metrics are made up at a higher level when */
      /* needed.                                          */
      metrics->vertBearingX = 0;
      metrics->vertBearingY = 0;
      metrics->vertAdvance  = 0;
    }
    break;

  case 6:
  case 7:
  case 9:
    /* variable big metrics */
    if ( FT_STREAM_READ_FIELDS( sbit_metrics_fields, metrics ) )
      goto Exit;
    break;

  case 5:
  default:  /* constant metrics */
    if ( range->index_format == 2 || range->index_format == 5 )
      *metrics = range->metrics;
    else
      return SFNT_Err_Invalid_File_Format;
 }

Exit:
  return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    crop_bitmap                                                        */
/*                                                                       */
/* <Description>                                                         */
/*    Crops a bitmap to its tightest bounding box, and adjusts its       */
/*    metrics.                                                           */
/*                                                                       */
/* <InOut>                                                               */
/*    map     :: The bitmap.                                             */
/*                                                                       */
/*    metrics :: The corresponding metrics structure.                    */
/*                                                                       */
static void
crop_bitmap( FT_Bitmap*       map,
             TT_SBit_Metrics  metrics )
{
  /***********************************************************************/
  /*                                                                     */
  /* In this situation, some bounding boxes of embedded bitmaps are too  */
  /* large.  We need to crop it to a reasonable size.                    */
  /*                                                                     */
  /*      ---------                                                      */
  /*      |       |                -----                                 */
  /*      |  ***  |                |***|                                 */
  /*      |   *   |                | * |                                 */
  /*      |   *   |    ------>     | * |                                 */
  /*      |   *   |                | * |                                 */
  /*      |   *   |                | * |                                 */
  /*      |  ***  |                |***|                                 */
  /*      ---------                -----                                 */
  /*                                                                     */
  /***********************************************************************/

  FT_Int    rows, count;
  FT_Long   line_len;
  FT_Byte*  line;


  /***********************************************************************/
  /*                                                                     */
  /* first of all, check the top-most lines of the bitmap, and remove    */
  /* them if they're empty.                                              */
  /*                                                                     */
  {
    line     = (FT_Byte*)map->buffer;
    rows     = map->rows;
    line_len = map->pitch;


    for ( count = 0; count < rows; count++ )
    {
      FT_Byte*  cur   = line;
      FT_Byte*  limit = line + line_len;


      for ( ; cur < limit; cur++ )
        if ( cur[0] )
          goto Found_Top;

      /* the current line was empty - skip to next one */
      line  = limit;
    }

  Found_Top:
    /* check that we have at least one filled line */
    if ( count >= rows )
      goto Empty_Bitmap;

    /* now, crop the empty upper lines */
    if ( count > 0 )
    {
      line = (FT_Byte*)map->buffer;

      FT_MEM_MOVE( line, line + count * line_len,
                   ( rows - count ) * line_len );

      metrics->height       = (FT_Byte)( metrics->height - count );
      metrics->horiBearingY = (FT_Char)( metrics->horiBearingY - count );
      metrics->vertBearingY = (FT_Char)( metrics->vertBearingY - count );

      map->rows -= count;
      rows      -= count;
    }
  }

  /***********************************************************************/
  /*                                                                     */
  /* second, crop the lower lines                                        */
  /*                                                                     */
  {
    line = (FT_Byte*)map->buffer + ( rows - 1 ) * line_len;

    for ( count = 0; count < rows; count++ )
    {
      FT_Byte*  cur   = line;
      FT_Byte*  limit = line + line_len;


      for ( ; cur < limit; cur++ )
        if ( cur[0] )
          goto Found_Bottom;

      /* the current line was empty - skip to previous one */
      line -= line_len;
    }

  Found_Bottom:
    if ( count > 0 )
    {
      metrics->height  = (FT_Byte)( metrics->height - count );
      rows            -= count;
      map->rows       -= count;
    }
  }

  /***********************************************************************/
  /*                                                                     */
  /* third, get rid of the space on the left side of the glyph           */
  /*                                                                     */
  do
  {
    FT_Byte*  limit;


    line  = (FT_Byte*)map->buffer;
    limit = line + rows * line_len;

    for ( ; line < limit; line += line_len )
      if ( line[0] & 0x80 )
        goto Found_Left;

    /* shift the whole glyph one pixel to the left */
    line  = (FT_Byte*)map->buffer;
    limit = line + rows * line_len;

    for ( ; line < limit; line += line_len )
    {
      FT_Int    n, width = map->width;
      FT_Byte   old;
      FT_Byte*  cur = line;


      old = (FT_Byte)(cur[0] << 1);
      for ( n = 8; n < width; n += 8 )
      {
        FT_Byte  val;


        val    = cur[1];
        cur[0] = (FT_Byte)( old | ( val >> 7 ) );
        old    = (FT_Byte)( val << 1 );
        cur++;
      }
      cur[0] = old;
    }

    map->width--;
    metrics->horiBearingX++;
    metrics->vertBearingX++;
    metrics->width--;

  } while ( map->width > 0 );

Found_Left:

  /***********************************************************************/
  /*                                                                     */
  /* finally, crop the bitmap width to get rid of the space on the right */
  /* side of the glyph.                                                  */
  /*                                                                     */
  do
  {
    FT_Int    right = map->width - 1;
    FT_Byte*  limit;
    FT_Byte   mask;


    line  = (FT_Byte*)map->buffer + ( right >> 3 );
    limit = line + rows * line_len;
    mask  = (FT_Byte)( 0x80 >> ( right & 7 ) );

    for ( ; line < limit; line += line_len )
      if ( line[0] & mask )
        goto Found_Right;

    /* crop the whole glyph to the right */
    map->width--;
    metrics->width--;

  } while ( map->width > 0 );

Found_Right:
  /* all right, the bitmap was cropped */
  return;

Empty_Bitmap:
  map->width      = 0;
  map->rows       = 0;
  map->pitch      = 0;
  map->pixel_mode = FT_PIXEL_MODE_MONO;
}


static FT_Error
Load_SBit_Single( FT_Bitmap*       map,
                  FT_Int           x_offset,
                  FT_Int           y_offset,
                  FT_Int           pix_bits,
                  FT_UShort        image_format,
                  TT_SBit_Metrics  metrics,
                  FT_Stream        stream )
{
  FT_Error  error;


  /* check that the source bitmap fits into the target pixmap */
  if ( x_offset < 0 || x_offset + metrics->width  > map->width ||
       y_offset < 0 || y_offset + metrics->height > map->rows  )
  {
    error = SFNT_Err_Invalid_Argument;

    goto Exit;
  }

  {
    FT_Int   glyph_width  = metrics->width;
    FT_Int   glyph_height = metrics->height;
    FT_Int   glyph_size;
    FT_Int   line_bits    = pix_bits * glyph_width;
    FT_Bool  pad_bytes    = 0;


    /* compute size of glyph image */
    switch ( image_format )
    {
    case 1:  /* byte-padded formats */
    case 6:
      {
        FT_Int  line_length;


        switch ( pix_bits )
        {
        case 1:
          line_length = ( glyph_width + 7 ) >> 3;
          break;
        case 2:
          line_length = ( glyph_width + 3 ) >> 2;
          break;
        case 4:
          line_length = ( glyph_width + 1 ) >> 1;
          break;
        default:
          line_length =   glyph_width;
        }

        glyph_size = glyph_height * line_length;
        pad_bytes  = 1;
      }
      break;

    case 2:
    case 5:
    case 7:
      line_bits  =   glyph_width  * pix_bits;
      glyph_size = ( glyph_height * line_bits + 7 ) >> 3;
      break;

    default:  /* invalid format */
      return SFNT_Err_Invalid_File_Format;
    }

    /* Now read data and draw glyph into target pixmap       */
    if ( FT_FRAME_ENTER( glyph_size ) )
      goto Exit;

    /* don't forget to multiply `x_offset' by `map->pix_bits' as */
    /* the sbit blitter doesn't make a difference between pixmap */
    /* depths.                                                   */
    blit_sbit( map, (FT_Byte*)stream->cursor, line_bits, pad_bytes,
               x_offset * pix_bits, y_offset, metrics->height );

    FT_FRAME_EXIT();
  }

Exit:
  return error;
}


static FT_Error
Load_SBit_Image( TT_SBit_Strike   strike,
                 TT_SBit_Range    range,
                 FT_ULong         ebdt_pos,
                 FT_ULong         glyph_offset,
                 FT_GlyphSlot     slot,
                 FT_Int           x_offset,
                 FT_Int           y_offset,
                 FT_Stream        stream,
                 TT_SBit_Metrics  metrics,
                 FT_Int           depth )
{
  FT_Memory   memory = stream->memory;
  FT_Bitmap*  map    = &slot->bitmap;
  FT_Error    error;


  /* place stream at beginning of glyph data and read metrics */
  if ( FT_STREAM_SEEK( ebdt_pos + glyph_offset ) )
    goto Exit;

  error = tt_load_sbit_metrics( stream, range, metrics );
  if ( error )
    goto Exit;

  /* This function is recursive.  At the top-level call, we  */
  /* compute the dimensions of the higher-level glyph to     */
  /* allocate the final pixmap buffer.                       */
  if ( depth == 0 )
  {
    FT_Long  size;


    map->width = metrics->width;
    map->rows  = metrics->height;

    switch ( strike->bit_depth )
    {
    case 1:
      map->pixel_mode = FT_PIXEL_MODE_MONO;
      map->pitch      = ( map->width + 7 ) >> 3;
      break;

    case 2:
      map->pixel_mode = FT_PIXEL_MODE_GRAY2;
      map->pitch      = ( map->width + 3 ) >> 2;
      break;

    case 4:
      map->pixel_mode = FT_PIXEL_MODE_GRAY4;
      map->pitch      = ( map->width + 1 ) >> 1;
      break;

    case 8:
      map->pixel_mode = FT_PIXEL_MODE_GRAY;
      map->pitch      = map->width;
      break;

    default:
      return SFNT_Err_Invalid_File_Format;
    }

    size = map->rows * map->pitch;

    /* check that there is no empty image */
    if ( size == 0 )
      goto Exit;     /* exit successfully! */

    error = ft_glyphslot_alloc_bitmap( slot, size );
    if (error)
      goto Exit;
  }

  switch ( range->image_format )
  {
  case 1:  /* single sbit image - load it */
  case 2:
  case 5:
  case 6:
  case 7:
    return Load_SBit_Single( map, x_offset, y_offset, strike->bit_depth,
                             range->image_format, metrics, stream );

  case 8:  /* compound format */
    if ( FT_STREAM_SKIP( 1L ) )
    {
      error = SFNT_Err_Invalid_Stream_Skip;
      goto Exit;
    }
    /* fallthrough */

  case 9:
    break;

  default: /* invalid image format */
    return SFNT_Err_Invalid_File_Format;
  }

  /* All right, we have a compound format.  First of all, read */
  /* the array of elements.                                    */
  {
    TT_SBit_Component  components = NULL;
    TT_SBit_Component  comp;
    FT_UShort          num_components, count;


    if ( FT_READ_USHORT( num_components )           ||
         FT_NEW_ARRAY( components, num_components ) )
      goto Exit;

    count = num_components;

    if ( FT_FRAME_ENTER( 4L * num_components ) )
      goto Fail_Memory;

    for ( comp = components; count > 0; count--, comp++ )
    {
      comp->glyph_code = FT_GET_USHORT();
      comp->x_offset   = FT_GET_CHAR();
      comp->y_offset   = FT_GET_CHAR();
    }

    FT_FRAME_EXIT();

    /* Now recursively load each element glyph */
    count = num_components;
    comp  = components;
    for ( ; count > 0; count--, comp++ )
    {
      TT_SBit_Range       elem_range;
      TT_SBit_MetricsRec  elem_metrics;
      FT_ULong            elem_offset;


      /* find the range for this element */
      error = find_sbit_range( comp->glyph_code,
                               strike,
                               &elem_range,
                               &elem_offset );
      if ( error )
        goto Fail_Memory;

      /* now load the element, recursively */
      error = Load_SBit_Image( strike,
                               elem_range,
                               ebdt_pos,
                               elem_offset,
                               slot,
                               x_offset + comp->x_offset,
                               y_offset + comp->y_offset,
                               stream,
                               &elem_metrics,
                               depth + 1 );
      if ( error )
        goto Fail_Memory;
    }

  Fail_Memory:
    FT_FREE( components );
  }

Exit:
  return error;
}


/*************************************************************************/
/*                                                                       */
/* <Function>                                                            */
/*    tt_face_load_sbit_image                                            */
/*                                                                       */
/* <Description>                                                         */
/*    Loads a given glyph sbit image from the font resource.  This also  */
/*    returns its metrics.                                               */
/*                                                                       */
/* <Input>                                                               */
/*    face         :: The target face object.                            */
/*                                                                       */
/*    strike_index :: The current strike index.                          */
/*                                                                       */
/*    glyph_index  :: The current glyph index.                           */
/*                                                                       */
/*    load_flags   :: The glyph load flags (the code checks for the flag */
/*                    FT_LOAD_CROP_BITMAP).                              */
/*                                                                       */
/*    stream       :: The input stream.                                  */
/*                                                                       */
/* <Output>                                                              */
/*    map          :: The target pixmap.                                 */
/*                                                                       */
/*    metrics      :: A big sbit metrics structure for the glyph image.  */
/*                                                                       */
/* <Return>                                                              */
/*    FreeType error code.  0 means success.  Returns an error if no     */
/*    glyph sbit exists for the index.                                   */
/*                                                                       */
/*  <Note>                                                               */
/*    The `map.buffer' field is always freed before the glyph is loaded. */
/*                                                                       */
FT_LOCAL_DEF( FT_Error )
tt_face_load_sbit_image( TT_Face              face,
                         FT_ULong             strike_index,
                         FT_UInt              glyph_index,
                         FT_UInt              load_flags,
                         FT_Stream            stream,
                         FT_Bitmap           *map,
                         TT_SBit_MetricsRec  *metrics )
{
  FT_Error        error;
  FT_ULong        ebdt_pos, glyph_offset;

  TT_SBit_Strike  strike;
  TT_SBit_Range   range;


  /* Check whether there is a glyph sbit for the current index */
  error = tt_find_sbit_image( face, glyph_index, strike_index,
                              &range, &strike, &glyph_offset );
  if ( error )
    goto Exit;

  /* now, find the location of the `EBDT' table in */
  /* the font file                                 */
  error = face->goto_table( face, TTAG_EBDT, stream, 0 );
  if ( error )
    error = face->goto_table( face, TTAG_bdat, stream, 0 );
  if ( error )
    goto Exit;

  ebdt_pos = FT_STREAM_POS();

  error = Load_SBit_Image( strike, range, ebdt_pos, glyph_offset,
                           face->root.glyph, 0, 0, stream, metrics, 0 );
  if ( error )
    goto Exit;

  /* setup vertical metrics if needed */
  if ( strike->flags & 1 )
  {
    /* in case of a horizontal strike only */
    FT_Int  advance;


    advance = strike->hori.ascender - strike->hori.descender;

    /* some heuristic values */

    metrics->vertBearingX = (FT_Char)(-metrics->width / 2 );
    metrics->vertBearingY = (FT_Char)( ( advance - metrics->height ) / 2 );
    metrics->vertAdvance  = (FT_Char)( advance * 12 / 10 );
  }

  /* Crop the bitmap now, unless specified otherwise */
  if ( load_flags & FT_LOAD_CROP_BITMAP )
    crop_bitmap( map, metrics );

Exit:
  return error;
}

#endif /* FT_CONFIG_OPTION_OLD_INTERNALS */


/* END */
